CN210346776U

CN210346776U - Rectangular venturi differential pressure device

Info

Publication number: CN210346776U
Application number: CN201921035896.1U
Authority: CN
Inventors: 贺庆龙; 杨峰
Original assignee: Shanghai Langmei Fluid Control Technology Co ltd
Current assignee: Shanghai Langmei Fluid Control Technology Co ltd
Priority date: 2019-07-04
Filing date: 2019-07-04
Publication date: 2020-04-17
Anticipated expiration: 2029-07-04

Abstract

The utility model discloses a rectangle venturi differential pressure device, including measuring the body, survey buret body both ends department and all install and be equipped with flange, the measurement body above the intercommunication seted up just to get and press mouthful and negative to get and press mouthful, the measurement body from the upper reaches to low reaches that the fluid flows through be entrance, shrink section, throat and export section in proper order, just get and press mouthful the top of locating the entrance, negative get and press mouthful the top of locating the throat, shrink angle of contraction section department be 25-90. The utility model has the advantages that: the device has the advantages of unique structure, high linearity, wide range ratio, good repeatability, low required straight pipe section, suitability for measuring various media and the like.

Description

Rectangular venturi differential pressure device

Technical Field

The utility model relates to a flow measurement technical field specifically indicates a rectangle venturi differential pressure device.

Background

Differential pressure flowmeters have a long history and are most widely used in various flow meters. The flow rate is obtained by measuring the pressure difference generated by the fluid in the pipeline flowing through the throttling element and combining the known working condition conditions by taking the Bernoulli theorem and the flow continuity equation as basic principles. The differential pressure type flowmeter has more varieties, and the differential pressure type throttling device which is frequently used in the current market is as follows: orifice plates, venturis, nozzles, pitot tubes, and the like. The work of developing the modern flow measurement technology in China is relatively late, flow instruments needed in the early stage are imported from foreign countries, and the Venturi tube differential pressure device does not appear until the 50 s of the 20 th century. The venturi restriction is a standard restriction and is shown in figure 2.

At present, the disadvantages of the classical venturi differential pressure device are as follows:

1. the volume is large, the structure length must be manufactured according to the ISO-5167, otherwise the required precision cannot be achieved;

2. due to the strict regulation of ISO-5167 on the classical Venturi structure, the maximum/minimum flow ratio of the flow measurement range is only 3:1-5:1, and the flow measurement with large flow change amplitude is difficult to meet;

3. the front straight pipe section and the rear straight pipe section which are required to be matched with the classical venturi differential pressure device are too long, and the requirements are difficult to meet on the common site;

4. the measurement accuracy of the fluid with low flow rate and low Reynolds number is not good.

SUMMERY OF THE UTILITY MODEL

The utility model discloses a solve foretell various problems, provide a unique structure, linearity height, range than wide, good reproducibility, required straight tube section low, be applicable to the rectangle venturi differential pressure device who measures various media.

In order to solve the technical problem, the utility model provides a technical scheme does: the utility model provides a rectangle venturi differential pressure device, includes the measurement body, measurement body both ends department all install and be equipped with flange, the measurement body above the intercommunication seted up just get pressure mouth and negative pressure mouth, the measurement body from the upper reaches to the low reaches that the fluid flows through be entry section, contraction section, throat and export section in proper order, the positive pressure mouth of getting locate the top of entry section, negative pressure mouth of getting locate the top of throat, contraction section department the shrink angle be 25-90.

As a modification, the inlet section and the outlet section have a length of 55 mm.

As an improvement, the distance between the central axis of the positive pressure taking port and the end of the inlet section connected with the contraction section is 20 mm.

As a modification, the distance between the upstream end of the throat part and the negative pressure taking port is 1/2-1 throat diameter.

Compared with the prior art, the utility model the advantage lie in: when the utility model is arranged, the straight pipe section with equal diameter at the inlet is reserved, and the stability of the inlet flow is ensured; compared with a classical venturi, the contraction section has a large contraction included angle and a short length, and can accelerate fluid and increase differential pressure; a longer throat part is reserved, so that the abrasion of the throat part can be avoided, and the service life is prolonged; the diffusion section in the existing device is removed, the structure is simplified on the premise of ensuring the measurement precision, and the structural length of the throttling device is shortened.

When the utility model is used, the linearity is high, the repeatability is good, the differential pressure is high, the pressure loss is low, the contraction angle is larger, the transition section is shorter, the fluid acceleration is larger, the rectification effect is better, the influence of vortex, vibration and signal noise is greatly reduced, the flow field stability is obviously improved, and the measurement performance is closer to that of a classical venturi device; secondly, the utility model has small volume, low required straight pipe section, greatly reduced use cost and better self-rectification effect, and experiments prove that the measurement precision can be ensured only by the shorter straight pipe section at the upstream and downstream; finally, the utility model discloses a flow measurement range is wide, and measuring effect is very outstanding under high flow rate, high reynolds number, can do the accurate measurement under low flow rate, low reynolds number the same, therefore rectangle venturi flow measurement range is wider than classical venturi device.

Drawings

Fig. 1 is the utility model discloses a rectangle venturi differential pressure device's elevation structure sketch map.

Fig. 2 is the utility model relates to a left side view structure schematic diagram of rectangle venturi differential pressure device.

FIG. 3 is a schematic diagram of a classical venturi differential pressure device product.

As shown in the figure: 1. measuring a pipe body; 2. a connecting flange; 3. a positive pressure tapping; 4. a negative pressure port; 5. an inlet section; 6. a contraction section; 7. a throat; 8. an outlet section.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

With reference to fig. 1, 2 and 3, the rectangular venturi differential pressure device comprises a measuring pipe body 1, wherein connecting flanges 2 are respectively arranged at two ends of the measuring pipe body 1, a positive pressure taking port 3 and a negative pressure taking port 4 are communicated with the upper surface of the measuring pipe body 1, the measuring pipe body 1 sequentially comprises an inlet section 5, a contraction section 6, a throat portion 7 and an outlet section 8 from the upstream to the downstream through which fluid flows, the positive pressure taking port 3 is arranged above the inlet section 5, the negative pressure taking port 4 is arranged above the throat portion 7, and the contraction angle of the contraction section 6 is 25-90 degrees.

The length of the inlet section 5 and the outlet section 8 is 55 mm.

The distance between the central axis of the positive pressure taking port 3 and the end of the inlet section 5 connected with the contraction section 6 is 20 mm.

The distance between the upstream end of the throat part 7 and the negative pressure taking port 4 is 1/2-1 diameters of the throat part 7.

The utility model discloses a concrete implementation mode: when the utility model is used, the positive pressure taking port 3 is positioned at the upstream of the measuring pipe body 1 and is used for collecting positive pressure signals of fluid in the measuring pipe body 1, and the negative pressure taking port 4 is positioned at the middle-downstream (the middle of the straight-through section of the throat part 7) of the measuring pipe body 1 and is used for collecting negative pressure signals of the fluid in the measuring pipe; the utility model is used for reducing the fluid flow area, throttling and reducing pressure, and generating pressure difference between the upstream and the downstream; the positive and negative pressure taking ports are respectively welded with 1 pressure taking pipe, the pressure taking pipes are used for connecting a valve, a valve group, a differential pressure transmitter instrument and the like and are used for respectively guiding collected positive and negative pressure signals to the differential pressure transmitter instrument and the like.

The present invention and the embodiments thereof have been described above, but the description is not limited thereto, and the embodiment shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. In summary, those skilled in the art should understand that they should not be limited to the embodiments described above, and that they can design the similar structure and embodiments without departing from the spirit of the invention.

Claims

1. The utility model provides a rectangle venturi differential pressure device which characterized in that: the measuring pipe comprises a measuring pipe body (1), connecting flanges (2) are installed at two ends of the measuring pipe body (1), the upper surface of the measuring pipe body (1) is communicated with a positive pressure taking port (3) and a negative pressure taking port (4), the measuring pipe body (1) sequentially comprises an inlet section (5), a contraction section (6), a throat part (7) and an outlet section (8) from the upstream to the downstream through which fluid flows, the positive pressure taking port (3) is arranged above the inlet section (5), the negative pressure taking port (4) is arranged above the throat part (7), and the contraction angle of the contraction section (6) is 25-90 degrees.

2. The rectangular venturi differential pressure device of claim 1, wherein: the length of the inlet section (5) and the outlet section (8) is 55 mm.

3. The rectangular venturi differential pressure device of claim 1, wherein: the distance between the central axis of the positive pressure taking port (3) and the end of the inlet section (5) connected with the contraction section (6) is 20 mm.

4. The rectangular venturi differential pressure device of claim 1, wherein: the distance between the upstream end of the throat part (7) and the negative pressure taking port (4) is 1/2-1 diameters of the throat part (7).